Method of manufacturing metal cans and the like



July 1, 1969 M. L. ANTHONY 3,452,695

METHOD OF MANUFACTURING METAL CANS AND THE LIKE Original Filed Jan. 5, 1965 Sheet of s EXTRUDER u PRINTING STATION STATION l3 EXPANDlN STATION 28 CONFIGURATION CHART AXIALLY CORRUGATED CANS (NUMBER OF FACETS.)

14 78 NVE/VTOR.

METHOD OF MANUFACTURING METAL CANS AND THE LIKE Original .Filed Jan. 5. 1965 M. l... ANTHONY July 1, 1969 Sheet P 0 N M L 6/ w M RWVFVHN WE L L m M Y 8 July 1, 1969 ANTHONY 3,452,695

METHOD OF MANUFACTURING METAL CANS AND THE LIKE Original Filed Jan. 5. 1965 Sheet 3 of s T LL1ET5' FORM THIN-WALL METAL TUBING (As BY IIA EXTRUSION OR WELDING) EMBOSS TUBING FROM EXTERIOR, I7A

BOTH SIDES 23A 6 vi; 24 3 COIL TUBING, SHIP CUT INDIVIDUAL CAN TO POINT OF USE BLANKS FROM FLAT,

EMBOSSED TUBING cuT INDIVIDUAL I CAN BLANKS FROM SHIP CAN BLANKS,

FLAT EMBOSSED FLAT, T0 POINT TUBING I OF USE \24A L I I zsa T EXPAND CAN BLANKS 2eA APPLY BASES TO EXPANDED CAN 32A BODIES I F I L L -7- 37A APPLY LIDS T0 39A cANs INVENTOR.

MYRO/V L. ANTHONY W1 9 4pm) July 1, 1969 3,452,695

METHOD OF MANUFACTURING METAL CANS AND THE LIKE M. L. ANTHONY Sheet 4 of8 Original Filed Jan. 5, 1965 I'll /7 J M W July 1, 1969 M. 1.. ANTHONY 3,452,695

METHOD OF MANUFACTURING METAL CANS AND THE LIKE Original Filed Jan, 5. 1965 Sheet .6 of a INVEN TOR.

MYRON L. ANTHONY y 1, 1969 M. L; ANTHONY 3,452,695

METHOD OF MANUFACTURING METAL CANS AND THE'LIKE 1 Original Filed Jan. 5. 1965 Sheet 6 of s lNVE/VTOR.

MYRO/V L. ANTHONY y 1969 M. I... ANTHONY 3,452,695

METHOD OF MANUFACTURING METAL CANS AND THE LIKE FORM THIN-WALL METAL TUBING (AS BY 3H EXTRUSION OR WELDING) FLATTEN TUBING -3I3 PRINT TUBING 3Is M I I COIL FLATTENED TUBING, 324A CUT |ND|VIDUAL CAN SHIP To POINT OF use BLANKS FROM FLAT I TUBING cuT INDIVIDUAL CAN I BLANKS FROM FLAT s24 sI-IIP FLAT CAN TUBING 323A-- BLANKS TO POINT 1 OF USE T EX PAND CAN BLANKS I 328 EXPAND CAN BLANKS I 328A- AND EMBOSS IN EMBOSS EXPANDED SINGLE OPERATION BLANKS APPLY BASES TO 332 CAN BLANKS FILL -33? APPLY uos To CANS 339 INVENTOR.

MYRO/V L. ANTHONY BY m #w July 1, 1969 M. L. ANTHONY 3,452,695

I I METHOD OF MANUFACTURING METAL CANS AND THE LIKE Original Filed Jan. 5, 1965 Sheet 6 of s INVENTOR. MYRO/V L. ANTHONY United States Patent 3,452,695 METHOD OF MANUFACTURING METAL CANS AND THE LIKE Myron L. Anthony, La Grange, lll., assignor of twentythree and seventy-five hundredths percent to George W. Butler and Gladys A. Butler, River Forest, Ill., as trustees under George W. Butlers trust, twenty-three and seventy-five hundredths percent to Gladys A. Butler and George W. Butler as trustees under Gladys A. Butlers trust, and five percent each to Thomas E. Dorn, Clarendon Hills, and Norman F. Kloker, Elmhurst, Ill. Original application Jan. 5, 1965, Ser. No. 423,497, now Patent No. 3,401,826, dated Sept. 17, 1968. Divided and this application Dec. 4, 1967, Ser. No. 687,614

Int. Cl. B21d 51/12, 21/00 US. Cl. 113-120 14 Claims ABSTRACT OF THE DISCLOSURE High-strength thin-wall metal can blanks and cans, and methods of forming and sealing the can blanks and cans. The can blanks, in one embodiment, are fabricated in substantially completely flattened tubular form with either longitudinal or transverse flat-faced corrugations throughout most of the surface area of the blank. The longitudinal edges of the can blanks terminate in relatively flat reverse bends. For longitudinally corrugated cans, the blanks have an even number of corrugation facets and an odd integral number of pairs of facets to permit expansion of the blank into a rectangular can body symmetrical about a transverse longitudinal plane. Commercial messages or other identification data are printed or otherwise reproduced on the corrugations, in registry therewith, to display messages of variant form depending on the angle from which the can is viewed. The longitudinal ends of the cans are left free of corrugations to permit effective hermetic sealing.

In one disclosed method, a can is manufactured from a deformable metal tube by first flattening the tube, then embossing a series of individual lengths of the tube to form multiple flat-faced corrugations covering most of the surface area in each such length, with uncorrugated transition sections at the ends of each length. The individual lengths are then severed into individual can body blanks, the blanks are expanded without substantial modification of the corrugations, and end closure members are sealed into the unembossed ends to complete the cans. In another embodiment, the corrugations are formed in tubular stock without utilization of the flattening procedure described above.

CROSS REFERENCE TO RELATED APPLICATION This application is a division of application Ser. No. 423,497, filed Jan. 5, 1965, now Patent No. 3,401,826, issued on Sept. 17, 1968.

BACKGROUND OF THE INVENTION This invention relates to new and improved methods of fabricating hermetically sealed cans and similar containers, and unique filling and distribution techniques employed in conjunction therewith. The invention is especially advantageous as applied to the manufacture and utilization of hermetically sealed thin-wall metal cans, particularly aluminum cans, although other materials 3,452,695 Patented July 1, 1969 may also be utilized as described more fully hereinafter.

The conventional tin can, in its many structural forms, is perhaps the most prevalent type of package employed for foods, beverages, semi-liquid and liquid materials, and for other materials, such as granulated coffee, which require hermetic sealing during shipment and stor-\ age. The can is fabricated from thin gauge sheet steel which has been plated with tin or has been otherwise provided with a protective coating. The can body is usually fabricated in cylindrical form, most frequently of circular cross section, with a base sealed to one end of the cylinder. This body is then filled and a lid is sealed to the top of the can to complete the package.

In some instances, the conventional tinplate can is fabricated from appropriately coated sheet steel at the point of use. This technique, however, is economically practical only for large canning operations. For packaging plants having a moderate or relatively small volume, the investment required for can-manufacturing machinery is prohibitive. Consequently, plants of small and moderate size, which are much more numerous than really large canning installations, employ prefabricated can bodies which require only filling followed by crimping or other sealing of a lid onto the can body to complete the package. Thus, it is frequently necessary to ship relatively large quantities of empty cans from the manufacturing point to the point of use, a quite wasteful procedure.

Conventional tinplate cans are not satisfactory for the packaging of some products, particularly those products which may be adversely affected by contact with iron through any pores or other imperfections in the tinplate. This is particularly true with respect to alcoholic beverages such as beer, which spoil rapidly upon contact with iron. Beer cans fabricated from sheet steel require specialized protective coatings, usually resin coatings, to prevent contact between the can body and the contents of the can. Even with this resin coating technique, which is itself rather expensive, canned beer cannot be stored indefinitely but must be rotated in the warehouse stock because it will ultimately spoil through penetration of the protective coating. The capital equipment necessary for the manufacture of beer cans is elaborate and expensive and in commercial practice is limited to only a few locations. Consequently, large shipments of empty cans are required from the manufacturing points to the breweries or other canning installations.

Aluminum cans have been proposed for food packaging, for beer containers, and for other uses. Generally speaking, however, aluminum cans have been adopted commercially only in rather specialized applications because the amount of aluminum required for construction of a can that will withstand the same usage as a conventional tinplate can makes the aluminum cans excessively expensive. Thus, despite the fact that aluminum cans have minimal adverse effect upon alcoholic beverages such as beer, there has been only a quite limited use of aluminum beer cans. Moreover, the fabrication of cans and like containers from aluminum using conventional techniques still results in the expense of shipping empty containers from the point of manufacture to the cannery or other plant at which they are used.

It is a principal object of the present invention, therefore, to provide novel container structures and unique fabrication methods making it possible to ship pre-fabricated hermetically sealable can blanks in flattened compact form from point of manufacture to a cannery, brewery, or other location at which the containers are expanded, filled and sealed.

Another object of the invention is to afford a practical means for increasing the effective strength of a hermetically scalable can of thin metal so that it may be substituted for a conventional can without substantial loss of structural strength.

A related object of the invention is to provide a corrugated can construction making it possible to construct a thin-wall aluminum container having essentially the same structural characteristics and strength as a conventional tinplate can.

A corollary object of the invention is to provide a corrugated can structure affording maximum strength for minimum wall thickness, using aluminum, plated steel, or other metals in thicknesses ranging down to gauges usually considered as representing foil unusable for rigid can structures.

A further object of the invention is to provide a practical packaging system that permits shipment of a multiplicity of flattened hermetically scalable container blanks in nested relation with each other so as to require a minimum of shipping space.

A particular feature of the invention is the provision for unique geometrical relationships in corrugations in the can blanks that facilitate flat, nested shipment and further enable the fabrication of a variety of rectangular, elliptical or circular can bodies from a single form of prefabricated can blank.

Another object of the invention is to afford a new and improved continuous process for manufacturing hermetically sealable cans from seamless metal tubing, including aluminum tubing.

An additional object of the invention is to provide for prefabrication of hermetically sealable container blanks in continuous roll form so that a large number of cans may be fabricated from a single roll of prefabricated container blanks.

Another object of the invention is to provide for convenient and rapid erection of a can body that has been shipped in the form of a flattened blank, at a location where the can is to be fllled, by inexpensive apparatus of a low order of complexity.

A fundamental object of the invention is to provide a continuous can manufacturing process that may be accomplished with relatively simple and inexpensive machinery and that reduces costs with respect to shipment and storage of prefabricated cans prior to use and also reduces shipping and storage costs for the completed filled cans.

Accordingly, the invention relates to a method of manufacturing a metal can or like container from a deformable tube, comprising flattening the tube, and embossing the flattened tube to form therein a multiplicity of flat-faced corrugations, the corrugations covering a substantial portion of the total surface of the flattened tube. The flattened embossed tube is expanded into a cylindrical can body of given configuration (rectangular, round, or otherwise) without substantial modification of the corrugations. Closure members are subsequently mounted in the open ends of the can body to complete an enclosed container.

Other and further objects of the present invention will be apparent from the following drawings which, by way of illustration, show preferred embodiment of the present invention and the principles thereof and what is now considered to be the best mode contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be made as desired by those skilled in the art without departing from the present invention.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified perspective schematic illustration of a packaging system employing one embodiment of the present invention;

FIG. 2. is a chart illustrating preferred corrugation geometry for one form of the present invention utilized in the fabrication of rectangular cans;

FIG. 3 is a perspective view of a hermetically sealed vertically corrugated rectangular can fabricated in accordance with one embodiment of the invention and based upon the geometry chart of FIG. 2;

FIG. 3A is a detail perspective view illustrating a lid for the can of FIG. 3;

FIG. 4 illustrates a plurality of filled cans in nested arrangement ready for shipping;

FIGS. 5A and 5B illustrate one form of can blank constructed in accordance with the present invention in expanded and in collapsed form, respectively;

FIG. 6 illustrates a particular can blank constructed in accordance with the present invention after erection to afford a cylindrical can body of rectangular cross-section;

FIG. 7 illustrates the same container blank as FIG. 6 but erected to afford a cylindrical can body of square cross-sectional configuration;

FIG. 8 is a flow chart illustrating the method of the present invention pertaining to the packaging system illustrated in FIG. 1;

FIG. 9 is a plan view of a strip of flattened can bodies produced at an intermediate stage in the system of FIG. 1;

FIG. 10 is a longitudinal section view taken approximately along line 10'10 in FIG. 9;

FIG. 11 is an edge view of a portion of the flattened corrugated strip of can blanks of FIG. 9;

FIG. 12 is a transverse sectional view taken approximately along line 12-12 in FIG. 9;

FIG. 13 is a transverse sectional view taken approximately along line 1313 in FIG. 9;

FIGS. 14, 15, 16 and 17 are detail sectional views illustrating successive stages in one process for sealing a lid onto a can or like package constructed in accordance with the present invention;

FIG. 18 is a perspective illustration of another form of hermetically sealed can fabricated in accordance with the invention;

FIG. 19 is a plan view of an embossed strip of can blanks produced at an intermediate stage in the manufacture of the can illustrated in FIG. 18;

FIG. 20 is a perspective view of another form of hermetically sealed can constructed in accordance with the invention;

FIG. 21 is a plan view of an embossed strip of can blanks produced at an intermediate stage in the manufacture of cans of the kind shown in FIG. 20;

FIGS. 22, 23 and 24 are perspective views of additional embodiments of hermetically sealed cans constructed in accordance with the present invention;

FIG. 25 is a simplified schematic perspective view of apparatus for expanding a flattened tubular can body blank to usable form;

FIG. 26 is a detail view of the can-forming dies of the apparatus of FIG. 25 at an initial stage of their operation;

FIG. 27 illustrates the apparatus of FIG. 26 at a subsequent stage of operation;

FIG. 28 illustrates a modification of the can expansion apparatus of FIGS. 26 and 27;

FIG. 29 is a flow chart illustrating another embodiment of the method of the present invention;

FIG. 30 is a sectional view of one form of embossing apparatus that may be utilized in the present invention, particularly in conjunction with the method of FIG. 29;

FIG. 31 is a sectional view taken approximately as indicated by line 3131 in FIG. 30;

FIG. 32 is a detail sectional view illustrating the final operating position for the apparatus of FIGS. 30 and 31; and

FIG. 33 illustrates another form of embossing apparatus that may be utilized in carrying out the method of FIG. 29.

Manufacturing method I FIG. 1 illustrates a packaging system for manufacturing hermetically sealed cans in accordance with one embodiment of the present invention; this same embodiment is illustrated in the flow chart of FIG. 8. Packaging system 10 (FIG. 1) may start with an extruding apparatus 11 of conventional construction that produces a continuous seamless metal tube 12. The metal tube 12 need not be of circular cross-sectional configuration. However, in order to assure uniformity in thickness of the tube walls, circular-section tubing is usually desirable. Extruder 11 need not be physically incorporated in the system 10; fabrication of the hermetically sealed cans to be produced by the system may be initiated with seamless tubing purchased from a commercial source of supply. Aluminum tubing is preferred, but other thin-wall tubing may be employed, including tubing fabricated by welding or other techniques from flat strip.

In the initial portion of packaging system 10, metal tubing 12 is passed through a.rolling station 13. Rolling station 13 is provided with one or more pairs of rollers 14 which engage the tubing 12 and flatten the tubing as completely as possible. It should be understood that rolling station 13 may include several pairs of rollers or like flattening devices and that the transformation of the tubing 12 into the flattened strip 15 may be accomplished gradually in order to avoid undue deformation of the tubing walls, which might interfere with subsequent expansion of the tubing to the final form desired for the completed cans or might create weak spots in the cans. The flattening rollers may be relieved slightly at their ends to avoid undue deformation of the edges of the flattened strip 15. Evenly spaced indexing notches are also formed in the edges of strip 15, in rolling station 13, as described hereinafter.

From rolling station 13, the flattened metal tubing 15 is passed through a printing station 16. At printing station 16, successive longitudinal sections of the flattened tubing 15, defined by the indexing notches in the strip (see FIG. 9) are imprinted with identification data for the completed cans. The imprinted data may include advertising messages and pictures as well as appropriate information indicating the ultimate contents of the cans. The length of the flattened tubing 15 assigned to each imprinted section may vary, depending upon the desired ultimate height of the cans. The printing apparatus incorporated in station 15 may be of conventional character and may be essentially similar to the corresponding apparatus employed to imprint conventional tinplate cans.

From printing station 16, the flattened and imprinted metal tubing 15 is passed through an embossing station 17. In FIG. 1, embossing station 17 is shown as including a pair of opposed embossing rolls 18 which engage the opposite sides of the flattened metal tube. It should be understood that more than one pair of embossing rolls may be required, inasmuch as embossing station 17 is utilized to produce, in the flattened tube 15, a plurality of distinct corrugations of substantial depth. In FIG. 1, the corrugations 19 are shown as relatively long longitudinal corrugations, but other strengthening deformations of the flattened strip may be utilized as described hereinafter. corrugations 19, as shown in FIG. 1, do not extend continuously along the length of the flattened tubular strip 15. Instead, each individual can length or blank on the strip 15 is embossed with the corrugations, leaving uncorrugated transverse sections 21 between each of the can lengths.

It is not necessary to employ roll-type embossing equipment to form the corrugations 19', although this kindof embossing apparatus is usually preferable for high-volume continuous manufacture. A press-type embossing device may be utilized if desired. Regardless of the form of embossing apparatus used, care should be exercised to avoid significant contraction of strip 15 in width; the corrugations are achieved by stretching the metal.

From embossing station 17, the fiat, embossed, imprinted strip 15 is wound upon a drum 23.

Most of system 10 as described above, comprising rolling station 13, printing station 16 and embossing station 17, is usually located at a central can manufacturing plant. From the manufacturing location, the strip of can blanks is shipped, on drum 23, to a cannery, brewery, or other location at which the cans are to be used. At the cannery, strip 15 is unwound from drum 23 and is fed to a shearing station 24 that includes suitable shearing apparatus such as a reciprocating shear blade 25 Working against an anvil 26. Shearing blade 25 is actuated to sever the flattened tubular strip 15 at each unembossed intermediate section 21, producing a series of flat can body blanks such as the blank 27.

The next station 28 in system 10 expands each of the can body blanks 27 into a can body of cylindrical configuration. Throughout this specification and in the appended claims the terms cylinder and cylindrical are employed in the broad sense as referring to a configuration generated by movement of a straight line in a closed path about a parallel straight line, hence including cylinders of rectangular, square, elliptical and other cross-sectional configurations as well as of circular configuration. Expanding station 28 is described more fully hereinafter in conjunction with FIGS. 25-28. In system 10, the individual can body blanks are expanded to rectangular cylindrical form as shown by the can bodies 29.

The expanded can bodies 29 are moved along a conveyor 31 to a base station 3 2. At base station 32, a strip of pre-formed can bases 33 is brought into alignment with the individual can bodies 29. A crimping device 34- is actuated to crimp one of the can bases 33 into one end of each of the rectangular can bodies 29. This crimping operation may be essentially similar to the corresponding operation performed on conventional tinplate cans, as described hereinafter in connection With FIGS. 14-17. Other methods of sealing the bases in the cans may be utilized, as described in detail in the aforesaid original application Serial No. 423,497 and in the divisional application filed concurrently herewith.

From base station 32, each of the can bodies 29, complete with a sealed-in base 33, is moved onto a second conveyor 35. At the transition point between conveyors 31 and 35, an appropriate mechanism 36 may be utilized to invert each of the can bodies, so that the base 33 of each can body rests on conveyor 35 and the open end of the can body faces upwardly.

Continued movement of the partially closed can bodies along conveyor 35 brings each of the can bodies to a filling station 37. At filling station :37, the can body is filled, by appropriate metering and filling equipment represented in the drawing only by the outlet conduit 38, with the particular food, beverage, or other material to be stored in the can.

From filling station 37, the filled can bodies proceed along conveyor 35 to a lid station 39. At station 39, a strip of can lids 41, which may be essentially similar to bases 33, is fed into alignment with the can bodies on the conveyor. A crimping device 42 crimps or otherwise seals one of the can lids 41 onto each can, hermetically sealing the can and completing its construction. From station 41, the filled and sealed cans continue their move ment along conveyor 35 to a further packaging or storage location.

One important aspect of packaging system 10 is that it affords a practical and economical system for fabricating hermetically sealed cans from continuous seamless tubing. This is particularly advantageous as applied to the suitable for use as the tubing 12 can be readily formed from aluminum by conventional extrusion apparatus. The

use of a seamless tube as the initial and. basic portion of the can body eliminates completely the equipment normally used to solder, weld or otherwise bond a flat strip of tinplate or other metal into a tubular form. Moreover, any problem of potential leakage at seams in the can body is eliminated.

The corrugation of the individual can lengths afforded by embossing station 17 is also of substantial importance in connection with the present invention. To be economically practical, cans manufactured in accordance with the invention should be fabricated from stock which is of minimal thickness as compared to the stock used for ordinary cans. Indeed, it is desirable that the tube stock employed be as thin as possible in order to reduce the cost Of the cans to a minimum, particularly where aluminum is utilized in constructing the cans. But aluminum is not as strong as steel of corresponding thickness, by a factor of approximately two to one, depending upon the alloys being compared and their hardness. Moreover, cans of rectangular or square cross-sectional configuration, such as the can bodies 29, are somewhat weaker than cans of the circular cross-sectional configuration. The corrugations afforded in the flattened strip 15 at embossing station 17, however, which are retained in the completed can structure, add materially to the strength of the completed can. The corrugated construction utilized for the can bodies makes it possible to employ thin gauge material, comparable in cost to the materials employed for conventional cans, without substantial loss of strength. Moreover, the corrugated constructions employed in the invention provide additional advantages with respect to high thermal conductivity and the reproduction of striking advertising messages, as discussed more fully hereinafter.

Shipment of the completed can blanks, in strip form, from the central can manufacturing location to the cannery, is quite economical as compared with the shipment of empty cans. Shipping costs are frequently computed on the basis of carload lots or on the basis of a unit termed a measurement ton which is really a measurement of volume rather than Weight. Costs thus computed on a volume basis, as applied to empty cans, are quite high. Shipment of the can blanks in roll form, as on the drum 23, affords a major reduction in shipping costs because the space requirements for shipment of a given number of cans are tremendously reduced.

From the foregoing description of the packaging systerm 10 of FIG. 1, it will be apparent that the particular forms of apparatus illustrated therein are not essential to performance of the basic inventive method. FIG. 8 affords a flow chart of the method of the invention as carried out by packaging system 10 or by other comparable means. As shown in FIG. 8, the first step in the invention, step 11A, is to procure a supply of thin wall metal tubing. This tubing can be continuous seamless extruded tubing or may be fabricated by welding from a strip of flat stock. The wall thickness will depend to some extent upon the size of the cans to be fabricated, the material to be contained in the cans, and the metal or alloy used in fabrication of the cans. A wall thickness of four to six mills, for example, may be utilized for aluminum cans, using an alloy of moderate hardness, with the cans having a capacity of twelve ounces and used for liquid storage.

The thin wall tubing is flattened, as indicated by step 13A in the flow chart of FIG. 8. This is preferably done on a continuous basis by roller apparatus or by passing the tubing through a pair of converging platens or by other comparable means. Index notches are cut or otherwise formed in the flattened tubing to define individual can lengths. The flattened tubing is then imprinted, if desired, with an appropriate identification, advertising message, or the like, step 16A.

After the tubing is flattened and imprinted, it is embossed from the exterior, and from both sides, as indicated by step 17A in the flow chart. Again, roller embossing apparatus may be utilized to perform step 17A but it is equally practical to utilize an intermittent press device with appropriate embossing platens or other apparatus for this purpose.

Following embossing step 17A, the embossed flattened tubing is coiled on an appropriate reel or other coil form and is then ready to ship to the point of use as indicated by 23A in the flow chart of FIG. 8. At the cannery or other plant where the cans are required, the flattened and embossed tubing is cut into individual can blanks as indicated by step 24A. These individual blanks are then expanded to cylindrical form (step 28A). The ultimate configuration of the expanded can blanks is dependent upon the type of can required by the user. As explained more fully hereinafter, a particular can blank can be expanded into a cylindrical can body of rectangular, circular, square or virtually any other desired cross-sectional configuration.

The next step in the process is to apply a base to each of the expanded can blanks, step 32A. Any one of a number of different specific techniques may be employed to seal the has to the can body. Thus, the conventional crimping techniques used in the fabrication of ordinary tinplate cans are readily applicable to the can bodies constructed in accordance with the present invention. On the other hand, and particularly where aluminum is used as the material for the can bodies, more positive crimping methods and even cold pressure welding techniques may be employed, particularly where a high quality hermetic seal is sesential.

Once the base is sealed into the can body, the can body is filled with the material to be stored in the can, step 37A. Thereafter, it is only necessary to apply a lid to each can and to seal the lid into the can (step 39A). The sealing technique used for the lids may be the same as for the sealing of the bases into the can bodies.

From the flow chart of FIG. 8, it will be apparent that steps 23A may be eliminated where cans are manufactured complete, filled, and sealed at a single location. But a substantially continuous, one-location process of this sort is most practical, economically, at largevolume canning plants and hence is less commonly employed.

It is not essential to the present invention that the flattened can blanks be shipped in continuous strip form as illustrated in FIG. 1 and as described above in connection with FIG. 8. Instead, the shearing station 24, described in conjunction with FIG. 1 as being located at the cannery, may instead be located at the can manufacturing point. Under these circumstances, the individual can body blanks 27 are sheared from the continuous strip 15 at the central can manufacturing point as indicated by alternate stage 24B in FIG. 8. The individual flattened, embossed can blanks are then shipped to the cannery or other point of use in stacks rather than rolled on a drum. Shipment of the can bodies in the form of pre-sheared stacked blanks (alternate step 23B, FIG. 8) is just as economical as shipment in continuous strip form. The corrugated can blanks nest with each other and require a minimum of shipping space.

The equipment required at the cannery, starting with the expansion station 28, FIG. 1, is generally similar to canning equipment required for conventional tinplate cans. The expanding station 28 is an addition to the normal cannery requirements but represents only a relatively small added increment of cost relative to the cost of conventional in-plant canning equipment. Much of the complete conventional cannery equipment has been omitted from FIG. 1, such as the apparatus required to prepare and process the material being packaged in the cans. The base application station 32 and the lid application station 39 may constitute equipment essentially similar to that used to apply the lids to conventional tinplate cans. The metering and filling equipment employed with cans constructed in accordance with the invention may be essentially identical with the corresponding filling apparatus employed for ordinary tinplate cans and other competitive packages.

Can structures-rectangular, vertically embossed FIG. 3 illustrates a completed can constructed by the method of the present invention. As shown therein, can body 29 retains the corrugations 19 formed in the can body blank at embossing station 18 (FIG. 1). At the lower end of can body 29, the uncorrugated section 21A affords a smooth transition section into which the base 33 is crimped to close and seal the bottom of the can. Similarly, at the top of the can the uncorrugated transition section 21B affords a smooth joint with the lid 41 that is crimped or otherwise secured into the top of the can to complete the sealed package. The lid 41 of the completed container may be provided with a pull-up tab opener 42.

FIG. 4 illustrates the substantial economy that may be realized with rectangular cans constructed in accordance with the form illustrated in FIG. 3, insofar as storage space is concerned. As shown in FIG. 4, the individual can bodies 29 may be nested with each other to afford a compact group of cans. Six of the cans 29 are shown in nested relation in FIG. 4, but additional cans may be grouped together in any required number.

The phantom outline 44 in FIG. 4 illustrates the additional space that would be required for storage of six cans of conventional circular configuration having the same capacity as the rectangular cans 29. As will be apparent from FIG. 4, and particularly with reference to the packages of six cans used commercially for the sale of beverages, the storage space requirements are materially reduced with the rectangular cans of the present invention. Moreover, the cost of paperboard cartons and packages for six-can units or other commercial grouped units is materially reduced.

FIG. 3A illustrates, on a reduced scale, the form and configuration of the lid 41 for the completed can illustrated in FIG. 3. Lid 41 is of the same construction as base 33, except that the base has no opener tab 42. On cans where no opener tab is provided, the lid and base are identical to each other. As shown in FIG. 3A, lid 41 is a simple rectangular cup-shaped member having side walls or flanges 46 of limited height. The side walls 46 are crimped together with the edges of the can body 29 or otherwise sealed thereto as described more fully hereinafter.

One unique advantage afforded by the corrugated can structures of the present invention, such as the can shown in FIG. 3, pertains to advertising or identification materials imprinted upon the can bodies at the preliminary stage of manufacture in the printing station 15 (FIG. 1). The desired lettering, pictures, and other advertising or identification material may be imprinted in sections, being divided between portions appearing on oppositely facing facets of the corrugated side walls such as the facets 47 and 48 in FIG. 3. Thus, by looking at the can from the angle shown in FIG. 3, one particular message imprinted upon the unshaded facets 47 may be made visible; by viewing the can from a different direction, in which the shaded facets 48 are exposed, a substantially different image, message, or color is revealed.

In order to make it possible to erect or expand the can body blanks into substantially symmetrical rectangular vertically corrugated can bodies, from pre-embossed flattened tubular stock, certain geometrical considerations should be adhered to. It can be demonstrated that expansion of a flattened pre-corrugated can body blank, having complementary longitudinal corrugations throughout a major portion of the surface area, into symmetrical rectangular form, can be achieved by regulation of the number of corrugation facets and of the number of pairs of corrugation facets. Specifically, the can body blank should be formed with an even number of corrugation facets and with an integral number of pairs of corrugation facets in order to permit expansion of the blank into a can body that is symmetrical in configuration about a given transverse longitudinal plane. Furthermore, if it is desired to provide a can body of square or rectangular cross-sectional configuration, then the corrugation of the can body blank should afford an odd integral number of pairs of corrugation facets.

FIG. 2 is a chart of corrugation configurations comprising eight columns 51, 52, 53, 54, 55, 56, 57 and 58. Each column lists a total number of longitudinal corrugation facets that may be afforded in a can body blank. The first column 51 includes configurations providing an even number of corrugation facets and an odd integral number of pairs of corrugation facets. Can body blanks having the numbers of corrugation facets listed in column 51 may be expanded to afford symmetrical can bodies which are either Square or of at least one other rectangular cross-sectional configuration, as described more fully hereinafter.

Columns 52, 54, 56 and 58 pertain to configurations in which there are an odd number of corrugation facets. A can body having an odd number of corrugation facets cannot be achieved by ordinary embossing or similar metal-forming procedures applied to a flattened tubular blank, since the odd number of facets requires differing treatment of the two opposed sides of the flattened tube. Consequently, it is not practical to construct can body blanks having the numbers of corrugation facets listed in columns 52, 54, 56 and 58 by embossing the flattened tubing.

If an even number of pairs of longitudinal corrugation facets are provided, it is not possible to expand the can blank into either a rectangular or square shape or any close simulation thereof without substantial deformation of one or more portions of the corrugations. The reason for this is that it requires three corrugation facets or panels encompassing the reverse bends at the two edges of the flattened corrugated tubing to provide for two of the four corners of the expanded can body, as is illustrated and described more fully hereinafter in connection with FIGS. 5 through 7. Thus, although it is readily possible to fabricate can body blanks having even numbers of pairs of corrugation facets as listed in columns 53 and 57 of FIG. 2, such blanks are not ordinarily usable for the manufacture of rectangular can bodies where the tubing is flattened completely with two direct reverse bends, as in the system described in FIG. 1, because the expanded can bodies would be irregular and unsightly in configuration.

Column 55, however, does list additional combinations of facet members that may be employed in longitudinally corrugated cans constructed in accordance with the system illustrated in FIGS. 1 and 8. That is, a can body blank constructed with the number of corrugation facets listed in any portion of column 55 affords an even number of corrugation facets and an odd number of pairs of corrugation facets. These particular combinations, however, can only be erected to afford rectangular can bodies having sides of different lengths and cannot be expanded to afford square can bodies.

The smallest reasonably usable number of longitudinal corrugation facets listed in column 51 of FIG. 2 is eighteen. FIG. 5B illustrates a corresponding flattened corrugated can body blank, shown in cross-section, having eighteen corrugation facets. The individual corrugation facets are identified in FIG. 5B by letters A through R. The right-hand edge of the can body blank comprises a second reverse bend affording the corrugation facets I and J.

Expansion of the can body blank 61 into a substantially square can body is shown in FIG. 5A. As shown in FIG. 5A, expansion of the can body blank 61 results in the formation of one corner that includes the three individual corrugation facets I, J and K, facets I and I having initially formed the right-hand reverse bend of the flattened blank, FIG. B. Similarly, the opposed corner of the expanded can body includes the three individual corrugation facets A, B and R from the reverse bend at the opposite edge of the blank. The remaining two corners of the expanded square can body each include two corrugation facets. Thus, one corner is affordded by the corrugation facets or panels E and F and another by the elements N and O, bent slightly from their initial corrugation angles but still extending in the same general directions relative to each other. It will be observed that the expanded can body is essentially symmetrical about a transverse plane indicated in FIG. 5A by the phantom line 62.

The can body blank 61 could also be expanded into a rectangular form other than a square. This could be accomplished by forming one corner with the corrugation facets C and D and another with the opposed pair L and M. It will be recognized that the resulting can configuration would not be particularly attractive but this is due primarily to the fact that the can body blank 61 illustrated in FIGS. 5A and 5B includes only a minimum number of corrugation facets.

FIG. 6 illustrates a can body 63 erected from a corrugated blank having a total number of seventy-four corrugation facets and thus affording thirty-seven pairs of corrugation facets. Two of the corners 64 and 65 of the can body 63 each include three corrugation facets; these corners include the two reverse bends at the opposite edges of the original flattened and corrugated can body blank. The two remaining corners 66 and 67 each include only two corrugation facets. The right and lefthand sides 68 and 69 of the can body 63, from corner to corner, each include a total of twenty-eight corrugation facets. The upper and lower sides 72 and 73 of the can body, as shown in FIG. 6, each include a total of thirty-six corrugation facets. Thus, it is seen that the can body 63 is of rectangular configuration having an aspect ratio of nine to seven. Can body 63 is symmetrical about a transverse plane indicated by the phantom line 74 extending through the corners 64 and 65. It will be recognized that the rectangular cylindrical can body 63 is also symmetrical about the transverse plane taken through the corners 66 and 67.

FIG. 7 illustrates a can body 83 expanded from a corrugated blank that is in all respects identical to the blank used to form the can 63 of FIG. 6. Again, the can body 83 has two corners 84 and 85 that are each formed by three individual corrugation facets, these being the corners of the can body formed from the reverse bend edge portions of the corrugated blank. The remaining corners 86 and 87 each include only two corrugation facets and are formed from the central portion of the corrugated blank. In this instance, each of the four sides 88, 89, 92 and 93 includes thirty-two corrugation facets, so that the aspect ratio of the can body 83 is unity and the can body is essentially square in cross-sectional configuration. The can body 83 is symmetrical with respect to a transverse plane, indicated by the phantom line 94, through corners 84 and 85. Indeed, the can body 83 is essentially symmetrical about any transverse plane taken through the geometrical center of the can body.

As pointed out above, can bodies such as the members 63 and 83 illustrated in FIGS. 6 and 7 cannot be constructed with an odd number of longitudinal corrugation facets, where the corrugations are of equal size and extend throughout the surface of the can, and cannot be practically formed by embossing a flattened tube from the exterior sides thereof. If the corrugations total an even number of pairs of corrugation facets, then it is not possible to utilize three individual facets for the reverse-bend corners, such as the corners 84 and 85 in FIG. 7, and at the same time maintain an equal number of corrugation facets on the sides of the container. Moreover, if an even number of pairs of corrugation facets are employed, it is necessary to flatten or even to reverse one of the embossed corrugations when the can blank is expanded to form a can body. This necessitates metal forming equipment of substantial size at the location at which the can blanks are expanded and effectively dissipates many of the advantages of the present invention.

FIGS. 9 through 13 afford detailed views of the embossed strip of can blanks issuing from the embossing station 17 of the system 10, FIG. 1. As clearly illustrated in FIG. 9, adjacent can blanks 101, 102 and 103 are separated by an intervening unembossed section 21 of the flattened corrugated tube 15. Preferably, indexing notches 104 and 105 are formed in the edges of the unembossed portion 21 of the tubing between adjacent can body blanks such as blanks 101 and 102, before imprinting of the flattened blanks. A similar pair of indexing notches 106 and 107 identify the point of separation between the adjacent blanks 102 and 103. These indexing notches afford a convenient means for assuring precise indexing of the printing on the can blanks and accurate severing of the individual can blanks from each other with uniform lengths, thereby assuring the fabri cation of cans of uniform capacity.

As indicated by the detail views, FIGS. 10 through 13, embossing of the corrugations 19 is preferably symmetrical with respect to the flattened tubing. The flattening of the tubing is maintained substantially uniform throughout the width of the tubing to avoid deformation of the completed cans. The depth of the corrugations 19 is of course dependent upon the width of the flattened tubing 15 and the number of corrugations required in the completed can. In the illustrated construction, the corrugations 19 are of uniform depth, and this construction is preferred because it affords a more uniform outward appearance for the container and because there is less likely to be difficulty in stacking the flattened containers for shipment. However, variations in the depths of the corrugations for special visual effects can be effected without substantial sacrifice of the benefits of the invention. Care should be exercised to avoid flattening the edges of the tube too sharply, to avoid creating a weakened line longitudinally of each can. As shown in FIGS. 12 and 13, some relief may be permitted along the edges.

Sealing of cans The base and lid of each can may be effectively sealed into the can body by conventional crimping techniques employed in the manufacture of tinplate cans, by cold pressure welding, particularly when using aluminum, or by other practical and effective means for sealing a relatively flat lid into an open-ended can body. FIGS. 14 through 17 illustrate one practical procedure, a technique that is similar to the crimping procedures used in the manufacture of conventional cans.

As shown in FIG. 14, when lid 41 is to be sealed into expanded can body 29, the lid is placed within the upper opening of the can body, in the uncorrugated portion 213. A separate mechanism may be provided for holding lid 41 suspended in the illustrated position in FIG. 15, or the lid may be supported by the internal projecting portions of the corrugations 19. Preferably, lid 41 is held in place by a slight draft to the flanges 46. It should be noted that the uncorrugated transition portion 21B of can body 29 terminates below the upper edge 111 of lid 41.

Sealing of can lid 41 into can body 29 is accomplished simply by bending the upwardly extending flange 46 of can lid 41 over the edge of the can body transition section 213 and crimping the two together. This crimping operation is illustrated at intermediate stages in FIGS. 15 and 16 and is shown in its completed form in FIG. 17. The flange 46 of lid 41 and the uncorrugated portion 218 of the can body afford a continuous sealed bead around the edge of the can and provide adequate hermetic sealing for most applications. If desired, sealing compound can be used, coating the sealing flanges 46 and 21B, and will accumulate in the areas 112 and 113 (FIG. 17) to further reduce the possibility of an inadequate seal.

Can structure modification The container illustrated in FIG. 3 is of rectangular configuration and is vertically embossed throughout virtually its entire surface area, the only uncorrugated portion of the surface being the two transition sections 21A and 21B at the ends of the can which provide a convenient and effective means for sealing a lid and a base into the can. A construction of this kind is strong and compact, yet may be inexpensively manufactured, particularly in accordance with the system described in connection with FIGS. 1 and 8. On the other hand, a number of modifications and variations may be made, with respect to the can configuration and the alignment and distribution of the strengthening corrugations, without departing from the present invention and, indeed, retaining most of the advantages of the initially described embodiment. Moreover, some of the modifications afford special advantages of their own.

FIG. 18 illustrates a container 201 constructed in accordance with another embodiment of the present invention; FIG. 19 is a plan View of an embossed strip of can blanks utilized in manufacturing can 201. Referring to FIG. 18, it is seen that container 201 is of rectangular configuration, the drawing showing two side walls 202 and 203 of the can together with the can lid 204. The base of the can may be essentially identical with lid 204. The remaining side walls of the can are identical in construction to walls 202 and 203.

Container 201 is not provided with vertical corrugations as in the previously described embodiment. Rather, container 201 is embossed, in manufacture, to afford a multiplicity of horizontally extending corrugations in the side walls thereof. On the front wall 203, there are two sets of horizontal corrugations, an upper group 205 and a lower group 206. The horizontal corrugations in both groups 205 and 206 extend virtually the full width of the can, leaving only narrow uncorrugated strips 207 and 208 at the corners. The smooth, uncorrugated strip 208 extends around the corner from the front wall 203 to the side wall 202 of container 201, wall 202 being provided with two groups of horizontal corrugations 211 and 212 aligned with groups 205 and 206 respectively on the front wall. The horizontal corrugations 211 and 212 extend for virtually the entire width of the side wall, leaving only the narrow strip 208 at one side and a similar narrow uncorrugated strip 213 at the opposite side of the corrugations.

On the front wall 203 of can 201, the upper and lower groups of corrugations 205 and 206 are separated by a relatively narrow uncorrugated area 214. Area 214 may be utilized for mounting of an adhesively secured identification label or for imprinting the can with data identifying the can contents. As noted above, in connection with the embodiment of FIG. 3, the corrugated portion of can 201 may be imprinted with advertising and basic identification material. The label or other identification applied to the can in the unembossed medial portion 214 thereof makes it possible to aflix specific identification data to a can structure used for a general line of related products. By way of example, if cans such as can 201 are utilized for the packaging of soup, the advertising and identification data imprinted or otherwise applied to corrugated sections 205 and 206 may be of a general nature identifying the manufacturer and indicating that the product contained within the can is soup. A small adhesive label or small imprint applied to uncorrugated section 214 may then be utilized to identify the particular variety of soup within the individual can, distinguishing it from other kinds of soup sold under the same general brand.

With respect to can 201, certain important considerations should be observed. In the first place, a major portion of the total can surface is embossed to afford a multiplicity of corrugations, as clearly illustrated in the drawing. It is not sufficient to afford a few widely spaced corrugations or rings in the can structure. To achieve the strength necessary for adequate protection of the can contents while utilizing thin-gauge materials, most of the can surface should be embossed to afford the desired strengthening corrugations. In the can illustrated in FIG. 18, the corrugations cover about sixty-five to seventy percent of the total can surface. They should be utilized throughout at least sixty percent of the can surface. This results in a can structure that is fully embossed, in accordance with the present inventive concept, affording the requisite strength to the completed can structure despite the use of thin-gauge material in forming the can walls. In this specification, and in the appended claims, the term fully embossed is defined as requiring embossing of sixty percent or more of the surface area of the can body.

In other respects, can 201 is essentially similar to the can described hereinabove in connection with FIG. 3. Thus, narrow upper and lower portions 214 and 215 of the can body are left uncorrugated to provide a smooth transition for sealing the lid and the base to the can. Can lid 204 may be provided with a suitable opener tab if desired.

FIG. 19 illustrates an embossed strip 217 of flattened can body blanks utilized in the manufacture of cans such as the can 201 of FIG. 18. The can blank strip 217 is formed from tubular stock, flattened and subsequently embossed, in flattened form, in the manner described hereinabove in connection with FIG. 1. As shown in FIG. 19, two narrow strips 207 and 213 are left free of em'bo-ssures at the edges of the flattened strip of can blanks 217; when the can blanks are expanded as described in connection with FIG. 1, and discussed in greater detail hereinafter, strips 207 and 213 (FIG. 19) form two corners of the can body (FIG. 18). The intermediate unembossed strip 208 makes it possible to form an intermediate corner in the can body without breaching the metal, as might occur if the horizontal embossures were carried across the entire width of the strip.

FIG. 20 illustrates a container 221 that is generally similar to can 201 of FIG. 18 but is embossed in accordance with a somewhat different pattern. In container 221, which is of rectangular configuration, the front wall 223 is provided with upper and lower embossed areas 225 and 226 separated by an intermediate unembossed section 238 that may be utilized for applying a specific identification label or imprint to the can. In this instance, however, neither horizontal embossure nor vertical embossure are employed. Instead, each of the upper and lower embossed areas 225 and 226 are embossed in a linear intersecting pattern, the lines of embossure extending normal to each other and at angles of 45 to the horizontal and vertical sides of the can. This results in a diamond-shape pattern of embossure which affords a strong structure resistant to bending and to casual indentation in virtually any direction. This configuration for the embossure affords excellent strength characteristics. It does not permit convenient use of variant messages imprinted upon differently aligned faces of a linear embossure pattern, as described above in connection with the can of FIG. 3 and as could be utilized also on the horizontally embossed can of FIG. 18. However, attractive general identification can be imprinted upon the wall areas 225 and 226, making due allowance for some distortion as a result of embossure of the can walls.

The side wall 222 of can 221 is also provided with upper and lower embossed sectors 231 and 232. As in the can of FIG. 18, narrow corner portions 227, 228 and 229 are left free of em'bossure so that the can can be expanded to rectangular form without breaching the can wall. Moreover, and as in the previously described embodiments, narrow upper and lower edges 234 and 235 are left unembossed to provide for a smooth transition section at each end of the can body into which the lid and base of the can may be hermetically sealed.

FIG. 21 illustrates a strip 237 of flattened tubular can blanks, embossed after flattening, that may be utilized in constructing can 221 of FIG. 20. As most clearly shown in FIG. 21, the can body blanks are fully embossed, the corrugations extending throughout the major portion of the surface areas of each can blank. The total area of the embossed sectors 225, 226, 231 and 232 should be at least equal to one-half the total area of an individual can blank and preferably substantially more thn one-half.

FIG. 22 illustrates another embodiment of a container constructed in accordance with the present invention. The metal can 241 shown in FIG. 22 is quite similar to can 221 of FIG. in that it includes a plurality of upper and lower sectors 245, 246, 251 and 252 of diamondshaped embossures. In this instance, however, the can is not expanded to rectangular configuration; rather, a cylindrical configuration of circular cross-section is employed. In can 241, in addition, the medial portion 247 of the can, between the upper and lower embossed areas, is embossed to afford a rib 248 girdling the can. Rib 248 may be interrupted at two points corresponding to the edges of the flattened embossed strip of can blanks if the can body for container 241 is fabricated in accordance with the method of FIGS. 1 and 8. Using this technique, one semi-circular segment of rib 248 projects outwardly of the can and a second semi-circular segment projects inwardly of the can. On the other hand, if the alternative fabricating system described hereinafter in connection with FIG. 29 is utilized, a continuous rib 248 can be formed around the entire periphery of the can, projecting either inwardly or outwardly of the can as desired.

On container 247, the vertical unembossed portion 249 of the can wall between embossed section-s 245 and 251 may be employed to apply an identifying label or imprint to the can. Any of the other narrow unembossed portions of the can separating the embossed segments thereof may 'be utilized for a similar purpose. On the other hand, it should be recognized that the upper portion of the can need not be completely consistent with the lower portion; for example, the embossed areas 246 and 252 of the can may be merged to eliminate entirely the unembossed section 253 in the form shown in FIG. 22. Furthermore, if desired, additional circular ribs such as the embossed rib 248 may be incorporated in the can structure.

The lid and base of container 241 may be essentially similar in construction to the lid and base elements described above except that they are of circular configuration rather than being rectangular. Alternatively, elliptical or other cross-sectional configurations can be utilized for the cylindrical can bodies and their mating bases and lids if preferred.

FIG. 23 illustrates another circular can or container 261 that is somewhat similar to can 251 of FIG. 22. In this instance, the upper portion 262 of the can body wall is provided with a multiplicity of vertical embossed corrugations. The corrugated sector 262 extends around the complete periphery of the can. The lower portion 264 of the can is similarly provided with sets of vertically extending embossed indentations or corrugations.

The central peripheral portion 265 of can 261 is free of the vertical embossures employed in the upper and lower sectors 262 and 264. This part of the can, however, is embossed to afford a strengthening rib or corrugation 266 that extends around approximately one-half of the can. A similar corrugation or rib 267 girdles the remaining half of the can periphery at the central portion of the can. The short unembossed sector 268 separating the two rib sections 266 and 267 corresponds to the edge of the flattened tubular can strip, when embossed in accordance with the system of FIGS. 1 and 8, and, consequently, affords a connecting vertical rib 269 between the upper and lower embossed sections. Using the other system embodiment described hereinafter in connection with FIG. 29, a complete continuous rib can be provided to replace the interrupted rib structure 266, 267; the short connecting vertical corrugation 269 being omitted. As before, suitable base and lid members may be sealed into can 261. Moreover, can 261 may be formed in an elliptical or other cross-sectional configuration as desired.

FIG. 24 illustrates yet another container 271 of circular cross-sectional con-figuration. Can 271 is embossed with a series of vertically extending corrugations 272 that extend essentially the full height of the can. In this regard, it should be noted that the can 271 can be formed directly from the blank or can body 29 illustrated in FIGS. 9-13. That is, the can blank for the circular can may be the same as the can blank for a rectangular or square can. If deemed essential to a particular application, a minor portion 273 of the can surface may be left smooth and free of corrugations 272 for the application of a specific identification label or imprint. In all other respects, can 271 is essentially similar to those described above. Note that can 271 has two ribs or corrugations with three facets, like corner corrugations 64 and 65 (FIG. 6) formed by expansion of the edges of the flattened tubular blank.

In each of the can structures of the present invention, as noted above, it is important that a major portion of the can surface be embossed to afford strengthening rib structures so that thin gauge material may be used in the fabrication of the can bodies. It is equally important that the embossure be of suflicient depth to afford ribs projecting inwardly and outwardly of the median line of the can wall, on each side thereof, for a distance at least equal to the thickness of the metal employed in the wall and preferably for a distance substantially greater than the wall thickness. Stated differently, shallow embossures that merely change the wall appearance and do not afford actual rib structures are not adequate to the present inyention. In this connection, reference may be made to FIGS. 12 and 13 which illustrated approximate minimum depths for the embossing of the corrugations relative to the wall thickness. Moreover, the corrugations should be formed by stretching the metal, not merely bending it, to increase the total wall area and work-harden the metal.

In addition to strengthening the can walls, fully embossed corrugated walls tend to increase thermal conductivity of the containers. This is a material advantage in packaging some goods, such as frozen foods and any foods and beverages that are ordinarily chilled before serving. Moreover, the working of the metal walls entailed in the embossing process is effective to workharden the metal, particularly with aluminum but also with other metals, further strenghtening the container walls.

Can expansion apparatus FIGS. 25 through 27 illustrate apparatus that may be employed to expand the individual can body blanks 27 produced at the shearing station 24 into the required configuration for the can bodies 29. That is, the apparatus shown in FIGS. 25 through 27 represents one form of equipment that may be employed at the expanding station 28 of the system 10 (FIG. 1). A modified form is illustrated in FIG. 28.

The can expansion apparatus 340 illustrated in FIG. 25 comprises a feeder apparatus 341 that is located at the left-hand side of the figure. Feeder apparatus 341 is employed to feed a series of the individual can blanks 27 from a stack 343 into the expansion apparatus. Feeder device 341 may comprise a plurality of guide members 344 mounted on a base 345, together with suitable means for supporting the stack 343 of can body blanks within the guide members. An appropriate mechanism is provided for progressively raising the stack 343 to maintain the topmost blank on the stack at the desired level for 17 feeding into expansion apparatus 340. This mechanism may be essentially similar to the corresponding mechanisms used in a variety of sheet-feeding applications; inasmuch as such devices are well known, no specific form of stack-lifting mechanism has been illustrated.

The blank-feeder apparatus 341 is also provided with a vacuum feeder member 346 that moves reciprocably from left to right in FIG. 25 to feed the topmost blank 27 from the stack 343 toward the right as seen in the drawing. Again, feeder apparatus of this nature is well known and the feeder element 346 has been shown only schematically. The initial movement of the upper blank 27 from the stack, in the direction of the arrow 347, is continued by a plurality of feed rolls 348.

Expansion apparatus 340 further includes a pair of travelling vacuum expansion members 3 51 and 352. The travelling expansion member 351 is mounted upon a pair of guide members 353 and 354. Similarly, expansion member 352 is supported upon a pair of longitudinal guide members 355 and 356. As shown in FIG. 26, the central portion of expansion member 351 includes a tubular extension 357 that projects downwardly from the expansion member and terminates in a vacuum gripping element 358. Suitable means are provided for moving vacuum gripper 358 in a vertical direction for a purpose described hereinafter. The construction of expansion member 352 is similar to member 351; it includes a forwardly projecting tubular member 359 that terminates in a vacuum gripper 360.

Expansion members 351 and 352 are aligned with a pair of expansion jaws 3 61 and 362. Power means (not shown) are provided for moving jaws 361 and 362 toward and away from each other.

At the outset of a can blank expansion operation, the two vacuum expansion members 351 and 352 are moved to the left from the position shown in FIG. 25 and into alignment with a can blank 27A that has been fed from the top of the stack 343. The two vacuum gripper elements 358 and 360 are thus brought into aligned engagement with the can blank, gripping the blank firmly. The vacuum connections for the grippers are generally illustrated by the hoses 363'- and 364.

Once a firm grip has been established between each of gripper elements 358 and 360 and can blank 27A, expansion members 351 and 352 are moved to the right to bring can blank 27A into expansion jaws 361 and 362 as shown in FIG. 26. Movement of the expansion members 351 and 352 is guided and controlled by guide members 353, 356 so that can blank 27A is accurately aligned in the two jaws 361 and 362. It should be noted that each of jaws 361 and 362 is provided with a pair of internal surfaces that are angularly oriented with respect to the flat can blank 27A.

With can blank 27A in the position shown in FIG. 26, the two jaws 361 and 362 are moved toward each other, pushing against the edges of the corrugated can blank. At the same time, vacuum grippers 358 and 360 are pulled away from each other to expand the central portion of the can blank. In this manner, the initial opening of the can blank is achieved, expanding the can blank toward the position shown in FIG. 27.

Ultimately, the two vacuum grippers 358 and 360 reach the limit of their vacuum hold on the can blank and are released from engagement with the can blank. Alternatively, the vacuum supply to the grippers can be shut off to release the grippers after the can blank has been partially expanded. Expansion devices 351 and 352 are then moved back toward their starting or feeding position to begin the next cycle of operation.

With the vacuum grippers out of the jaws, the inward movement of the jaws 361 and 362 is continued, forcing the can blank into conformation with the interior jaw faces to provide a completed expanded can body of the desired configuration. To assist in this expansion, the end faces of the jaws may be sealed off by suitable closure plates and compressed air may be forced into the interior of the can blank, from a suitable source, as indicated by the compressed air outlet 166 in FIG. 25.

It may also be desirable to afford a more positive can blank expansion action within the expander jaws. To this end, a pair of internal expander members may be inserted within the partially expanded can blank, during the final closing movements of the jaws to force the can blank outwardly into full conformity with the expander jaws. FIG. 28 illustrates an expansion arrangement of this kind, embodying two expander jaws 361A and 362A, the jaws being shown in the same relative position as jaws 361, 362 in FIG. 27. A pair of internal expander members 371 and 372 are inserted within the partially expanded can blank 27B in the jaws 361A, 362A. As jaws 361A, 362A continue to close, members 371, 372 move outwardly to assure full expansion of the can body.

Packaging sytem II FIG. 29 comprises a flow chart illustrating another form of the present invention that is closely related to the method described hereinabove in connection with the flow chart of FIG. 8 but that is modified somewhat with respect thereto. The initial step 311 of the packaging method shown in the flow chart of FIG. 29 is the same as the first step in the first-described method; a supply of thin-wall metal tubing is first procured. This tubing may be welded or extruded tubing or may be fabricated in any other suitable metal affording adequate strength characteristics. The metal may be aluminum and, indeed, this is usually preferred, but other types of metal tubing may be utilized in carrying out the method of the invention.

The thin-wall metal tubing is flattened as indicated by step 313 in FIG. 29 and is then imprinted with advertising, identification, or other pertinent data (step 316).

Thereafter, the flattened imprinted tubing may be coiled and shipped to the cannery, brewery, or other plant at which the tubing is to be used for fabricating hermetically sealed cans or like containers, as indicated by step 323 in the process chart of FIG. 29. At the point of use, step 324, individual can blanks are cut from the flattened imprinted tubing. These can blanks are expanded, step 328, and only then are embossed to afford the strengthening corrugations required in accordance with the present invention, step 317. It is thus seen that the embossing step 17A that was performed early in the method of FIG. 8 is performed at a substantially later time as step 317 in the modified method of FIG. 29.

The remaining steps in the initial method illustrated in the flow chart of FIG. 29 are the same as for the previously described embodiments. That is, the embossed expanded can bodies are first provided with suitable bases, the bases being sealed into the can bodies in accordance with any of the several techniques deescribed above. After application of the bases, step 332 in FIG. 29', the cans are filled (step 337). Finally, appropriate lids are applied to the can bodies and sealed thereinto, in step 339, to complete the hermetically sealed containers.

A further modification of the inventive method, also illustrated in FIG. 29, provides for severing of the individual can blanks from the flattened metal tubing at the point of initial manufacture. Thus, and as indicated by step 324A in FIG. 29, the individual can blanks may be cut from the continuous flattened tubing at the point of can manufacture, preferably after the desired advertising, identification, and other legends have been imprinted upon the can stock. This makes it possible to ship flattened individual can blanks to the point of use as shown by step 323A. Following this technique, the can blanks can be expanded and embossed, preferably in a single operation, at the point of use, as shown by stage 328A in the flow chart of FIG. 29.

Can embossing apparatus FIGS. 30, 31 and 32 illustrate one method and means by which individual can blanks can be fully expanded to their final cylindrical form and also embossed to afford a fully embossed can structure. As shown in FIGS. and 31, the combination expansion and embossing apparatus comprises a pair of external die members 251 and 252 which mate with each other and afford a completely enclosed die. The interior surface of die member 251 is formed with a series of teeth 253 and a corresponding plurality of teeth 254 are formed on the inner surface of die member 252. The teeth 253 and 254 in die members 251 and 252 define the corrugations to be formed in a can blank processed in the expansion and embossure apparatus 250.

Apparatus 250 further includes a tapered expansion cone 255 that extends upwardly through the central opening in the two die members 251 and 252 and that is con centrically aligned with the external die members. A plurality of individual expansion and embossure members 256 are disposed within die members 251 and 252 around the periphery of the expansion cone 255. Members 256, referred to hereinafter as the punch members of the embossing apparatus, are individually aligned with the depressions 257 and 258 between the teeth 253 and 254 in the inner surfaces of the die members 251 and 252. That is, for each slot or groove 257 around the interior surface of die member 251, there is a punch member 256, and the same relation applies to the notches or grooves 258 in the die member 252.

In placing the expansion and embossing apparatus 250 in use, a smooth, partially expanded uncorrugated can blank 261 is located within the two die members 251 and 252. The can blank is disposed between the two die members and the individual punch members 256 as shown in both FIGS. 30 and 31. With. the apparatus thus aligned, the expansion cone 255 is driven upwardly in the direction of the arrow 263 (FIG. 31) to drive punch members 256 radially outwardly into the notches or grooves 257 and 258 in the external die members.

Continued advancing movement of the expansion cone into apparatus 250 causes the punch members 256 to force the thin-wall can blank 261 outwardly into the grooves in the encompassing die members. The final position of the apparatus is shown in the detail view of FIG. 32, in which it is seen that the punch members force the metal of the can wall into each of the notches 257, completing expansion of the can body and simultaneously embossing the same with a plurality of relatively deep corrugations to complete a can body conforming to the requirements of the present invention.

In connection with the combined expansion and em bossure apparatus 250 of FIGS. 30-32, it should be noted that, where integrated manufacture is desired and the complete cans are manufactured at point of use, it is not necessary to start with a flattened tubular can. Instead, the starting material may be individual lengths of thinwall metal tubing in their original cylindrical configuration, whether of circular, rectangular, or other desired cross-section. Thus, can bodies fully corresponding to the present invention may be fabricated without preliminary flattening where there is no necessity for shipping the can bodies from one location to another.

On the other hand, and particularly in those instances where it is essential to ship the can bodies any substantial distance, the expansion and embossing apparatus 250 may be utilized with pre-flattened can bodies so long as the can bodies are partially expanded prior to the final expansion and embossing operation carried out in this device. It may also be noted that the can bodies need not be initially fabricated from a continuous length of tubing but can be manufactured on an individual basis by a drawing or extrusion operation of a small quantity of metal; a preferred manufacturing technique of this kind is described and claimed in the co-pending application 20 of Myron L. Anthony, Ser. No. 610,377, filed Jan. 19, 1967.

In the expansion and embossing apparatus 250, the die member grooves 257 and 258 and the individual punch members 256 do not extend the full height of can body 261. Rather, the punches and the mating die cavities terminate short of the full length of the can body so that the completed can body retains a smooth transition rim at each end into which appropriate base and lid members may be sealed.

Although apparatus 250 is shown in a form suitable for fabricating a can of circular cross-section, appropriate modifications may be made in the apparatus for expanding and embossing rectangular, elliptical, and other can shapes. Moreover, apparatus 250 is not limited to formation of multiple vertical corrugations in the completed can bodies but can be employed for horizontal corrugation patterns, as described above, as well. Small areas can be left smooth and uncorrugated, by appropriate modification of the embossing and expansion apparatus 250 for application of specific identification labels or imprints. Other forms of expansion apparatus, such as resilient pressure-expandable members, dual expander cones, or the like, may be utilized as described.

FIG. 33 illustrates another form of embossing apparatus that may be utilized with can bodies already expanded to their desired configuration, pursuant to that form of the system described hereinabove in connection with FIG. 29. The embossing apparatus 270 illustrated in FIG. 33 is particularly useful as applied to cans of circular crosssectional configuration.

The embossing apparatus 270 of FIG. 33 is quite simple; it comprises, essentially, a pair of embossing gears 271 and 272. The external embossing gear 271 has a multiplicity of embossing teeth 273 projecting downwardly of its periphery. The internal embossing gear 272 affords a corresponding multiplicity of radially projecting embossing teeth 274 that mesh with the teeth 273 of embossing gear 271. The two embossing gears are preferably of the same size and configuration, and are arranged so that the teeth on each gear interfit into the spaces between teeth on the other gear. It will be recognized that the teeth 274 on the internal embossing gear 272 need not be uniform and need not all extend for the full axial height of the gear provided any interruptions or variations in the embossing teeth are aligned with complemental variations in the pattern of teeth on the external embossing gear 271.

For an embossing operation, gears 271 and 272 are displaced from each other a short distance and a can body 275 is positioned between the two gears. The two gears are then brought together and are rotated relative to each other to emboss the can body with a multiplicity of corrugations 276. Of course, the pattern of teeth on the two gears 271 and 272 should provide the desired corrugations such as corrugations 276 throughout more than onehalf of the surface area of can body 275, producing a can body that is fully embossed in accordance with the present invention. Moreover, if there are any variations in the size, spacing, or other features of the embossing teeth, these factors should be correlated with the circumference of the can body to avoid multiple overlapping embossure of the can body.

In all of the several embossing techniques described hereinabove, an additional advantage is derived, over and above the strength imparted to the can bodies by the formation of the ribs or corrugations therein. The stretching and working of the metal that takes place in the embossing operation is effective to at least partially work-harden the metal, so that the can body is materially strengthened over and above the additional strength imparted by formation of the corrugations themselves. Thus, to at least a limited extent, the metal itself is made stronger by the embossing operation in addition to being given a stronger structural configuration.

In any of the embossing procedures, and as noted above, it is not suflicient merely to press a pattern into the surface of the metal; fully defined ribs or corrugations are necessary to provide the strong containers characteristic of the present invention. The overall depth of the corrugations should, at a minimum, be at least three times the thickness of the metal. That is, for metal walls of given thickness D, the metal should be bent outwardly of the center line of the can body by an amount at least equal to the same thickness D and should also be bent inwardly of the can body by the same amount, producing corrugations having a total effective height of three times D. Moreover, it is usually desirable to provide corrugations of substantially greater depth than this minimal limitation. In typical small containers used for the storage of beverages, foods, and the like, it is usually desirable to provide corrugations or ribs having an overall height of to 1 inch.

I claim:

1. The method of manufacturing a metal can or like container from a deformable tube comprising:

flattening said tube;

embossing the flattened tube to form therein a multiplicity of flat-faced corrugations, said corrugations covering a major portion of the total surface area of said flattened tube;

expanding said flattened embossed tube into a cylindrical can body of given configuration without substantial modification of said corrugations;

and mounting closure members of said given configuration in the open ends of said can body to complete an enclosed container.

2. The method of manufacturing metal cans or like containers from an elongated seamless metal tube comprising:

flattening said tube;

embossing the flattened tube to form a multiplicity of flat-faced corrugations therein, said corrugations covering a major portion of the total surface area of said flattened tube;

severing said flattened embossed tube to form a plurality of individual can body blanks each including an embossed length of said tube;

expanding each of said can body blanks into a cylindrical can body of given configuration without substantial modification of said corrugations;

and mounting closure members of said given configuration in the open ends of said can bodies to complete a plurality of enclosed containers.

3. A method of manufacturing metal cans or like containers, according to claim 2, in which spaced lengths of said flattened tube are embossed and are separated by uncorrugated transition portions of said tube, in which said tube is severed transversely of said transition portions so that said can blanks each terminate at each end in an unembossed sealing section, and in which said closure members are mounted in said sealing sections.

4. A method of manufacturing metal cans or like containers according to claim 3, in which said corrugations extend longitudinally of said can blanks.

5. A method of manufacturing metal cans or the like according to claim 4, in which said corrugations constitute an odd integral number of pairs of corrugation facets permitting expansion of said can blank into a can body symmetrical about a transverse longitudinal plane.

6. A method of manufacturing metal cans or like containers according to claim 3 in which the lines of embossure intersect to afford a diamond-shaped embossure pattern.

7. A method of manufacturing metal cans or containers according to claim 2 in which said flattened tube is imprinted, in a series of successive areas, with identification data in registery with said corrugations to give varying visual impressions dependent upon the angle from which the can body is viewed.

8. The method of manufacturing metal cans comprising the following steps in sequence:

(1) flattening a length of thin-wall relatively ductile metal tube at a first location;

(2) shipping said flattened tube length to a second lo cation; (3) expanding said flattened tube length into a cylindrical can body of given configuration at said Second location; and i (4) mounting closure members of said given configuration in the open ends of said can body, to complete a closed container;

A. said method comprising the additional step of embossing said tube length to form therein a multiplicity of flat-faced corrugations covering a major portion of the total surface area thereof, prior to step 4, said configuration remaining without substantial modification in said can body and in the completed can.

9. The method of manufacturing metal cans according to claim 8, in which said length of metal tube is a part of an elongated seamless metal tubing member including many such lengths, comprising the further step of severing said length from said tubing member subsequent to step 1 and prior to step 3.

10. The method of manufacturing metal cans according to claim 8 including the following additional steps:

imprinting said tube length with appropriate identification data prior to step A; and

severing said length of tube from an elongated substantially continuous tube subsequent to step 1 and prior to step 3.

11. The method of manufacturing metal cans according to claim 9, including the step of forming a series of equally-spaced indexing notches in the edges of the flattened tube prior to either of the additional severing and embossing steps.

12. The method of expanding a substantially completely flattened tubular can blank fully embossed from opposite sides to afford a multiplicity of corrugations therein, comprising:

securing a pair of gripper members to the opposed sides of said blank, at opposed points in the medial portions thereof, by vacuum;

pulling the opposed sides of said blank apart by relative movement of said gripper members to expand said can blank to cylindrical form;

and simultaneously forcing the edges of said blank in wardly to aid in expansion of said can blank. 13. The method of expanding a substantially completely flattened tubular can blank fully embossed from opposite sides to afford a multiplicity of corrugations therein, comprising:

enclosing said can blank in a two-part die having interior corrugations corresponding to the corrugations in said can blank, with the two parts of said die spaced beyond the edges of said can blank;

securing a pair of gripper members to the opposed sides of said blank, at opposed points in the medial portions thereof, by vacuum;

pulling the opposed sides of said blank apart by relative movement of said gripper members to expand said can blank toward cylindrical form; simultaneously moving the two parts of said die toward each other to force the edges of said blank inwardly and aid in expansion of said can blank; releasing said grippers from said can blank and removing the same from within said die; and continuing movement of the two parts of said die toward each other to complete expansion of said can blank to form a cylindrical can body.

14. The method of manufacturing a corrugated thinwall aluminum can body comprising:

forming a can body blank consisting essentially of a seamless thin-wall aluminum tube;

and thereafter embossing said can body blank to stretch References Cited portions thereof and form a multiplicity of sharply UNITED STATES PATENTS angled fiat-surfaced corrugations extending over major portion of the surface area of the can body 1,462,475 7/1923 Atkinson 113*120 blank, the depth of said corrugations exceeding three 262,086 11/1941 Barrow times the thickness of the tube wall, without substantially decreasing the wall perimeter. RONALD GREFE Puma); Emmmer' 

